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Zero-valent Iron Catalyze Hydrogen Peroxide And Sodium Persulfate Fenton-like Degrada Reactive Brilliant Orange X-GN

Posted on:2017-02-20Degree:MasterType:Thesis
Country:ChinaCandidate:Y LinFull Text:PDF
GTID:2311330536953046Subject:Environmental engineering
Abstract/Summary:PDF Full Text Request
As a public known refractory industrial wastewater,dyeing wastewater contains complex pollutant,alkalinity,color and high amount of organic compounds and it is not biodegradable.With the development of technology,finishing agent and new additives were used in printing and dyeing industry widely.It is necessary that to treat the dyeing wastewater efficiently.Fenton technology originates from 19 th centry and it is applied in treatment of wastewaters widely.However,the application of Fenton technology is limited by narrow reaction pH range,low Fe2+ utilization efficiency,large amount ferrous salts and iron-containing sludge.In order to overcome the limitations above and improve the Fenton technology,this study replaces Fe2+ and H2O2 with Fe0 and Na2S2O8 to build a novel heterogeneous Fenton system to degrade dyeing wastewater.Fe0/H2O2 hetergeneous Fenton system was built to degrade the azo dye reactive brilliant orange X-GN,this study investigates the effect of initial pH,the dosage of H2O2 and Fe0 and the reaction temperature on the X-GN removal.The iron leaching concentration after the reacton is investigated as well.The results show that Fe0/H2O2 hetergeneous Fenton system degrade the X-GN effectively with lower production of iron-containing sludge.When the initial X-GN concentration is 100 mg/L,initial pH is 3,Fe0 dosage is 1 g/L,H2O2 dosage is 5 mmol/L and reaction temperature is 30 oC,the X-GN removal efficiency is above 95% after 60 min reaction time,and the iron concentration after the reaction is lower than 1 mg/L.The UV-vis spectra analysis shows that the chromophoric group and benzene structure were destroyed during the Fenton reaction.However,the Fe0/H2O2 hetergeneous Fenton system is limited by the initial pH.When the initial pH is 3,the X-GN removal efficiency is 2.5,5 and 15 fold of the efficiency of the systems when the initial pH is 6,8 and 10,respectively.Fe0/Na2S2O8 hetergeneous Fenton system was built to degrade the azo dye reactive brilliant orange X-GN,this study investigates the effect of initial pH,the dosage of Na2S2O8 and Fe0 and the reaction temperature on the X-GN removal.The iron leaching concentration after the reacton is investigated as well.The results show that X-GN is degraded by Fe0/Na2S2O8 hetergeneous Fenton system effectively.With comparison to the Fe0/H2O2 system,the leaching iron concentration of Fe0/Na2S2O8 system is higher,but it is still lower than the traditional Fenton system.When the initial X-GN concentration is 100 mg/L,initial pH is 7,Fe0 dosage is 0.5 g/L,Na2S2O8 dosage is 1 mmol/L and reaction temperature is 30 oC,the X-GN removal efficiency is above 92.6% after 60 min reaction time,and the iron concentration after the reaction is lower than 2.2 m g/L.The optimum pH range of Fe0/Na2S2O8 system is broader than Fe0/H2O2 system.When the initial pH is between 2 and 9,the initial X-GN concentration is 100 mg/L,Fe0 dosage is 0.5 g /L,Na2S2O8 dosage is 1 mmol/L and reaction temperature is 30 oC,the X-GN removal efficiency is higher than 90% after 60 min reaction time.The effect of Fe0 dosage on t he X-GN removal efficiency of Fe0/Na2S2O8 system is not significant,and the Fe0 dosage is easy to control.When the X-GN concentration is 100 mg/L,initial pH is 7,Fe0 dosage range from 0.1 to 2 g/L,the Na2S2O8 dosage is 1 mmol/L,and the reaciton temperature is 30 oC,the X-GN removal efficiency is higher than 86.8% after 60 min reaciton time.Consider all the description above,Fe0/Na2S2O8 system can degrade X-GN effectively with a broad optimum pH range and low leaching iron concentration,and this system is not affected significantly by the Fe0 dosage.It is a promising wastewater treatment technology.
Keywords/Search Tags:Fe~0, Na2S2O8, heterogeneous Fenton-like reaction, reactive brilliant orange
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